Table 1 Clinicopathologic characteristics of patients with ALM and non-ALM classified into T1, T1a, and T1b groups.

From: Prognostic significance of acral lentiginous histologic type in T1 melanoma

 

T1

T1a

T1b

Characteristic

ALM (N = 129)

Non-ALMa (N = 699)

ALM (N = 82)

Non-ALMa (N = 454)

ALM (N = 47)

Non-ALMa (N = 245)

Sex, n (%)

  Male

42 (33)

355 (51)b

27 (33)

221 (49)c

15 (32)

134 (55)c

  Female

87 (67)

344 (49)

55 (67)

233 (51)

32 (68)

111 (45)

Age, years

      

 Median (range)

56.1 (9.8–99.4)

50.7 (2.3–7.7)c

55.7 (9.8–99.4)

49.1 (2.3–86.4)c

56.7 (21.3–85.4)

52.6 (15.8–87.7)c

Race/ethnicity, n (%)

  Caucasian

95 (78)

677 (97)b

59 (77)

439 (97)b

36 (80)

238 (97)b

  Hispanic

18 (15)

15 (2)

12 (16)

10 (2)

6 (13)

5 (2)

  Other

9 (7)

6 (1)

6 (8)

4 (1)

3 (7)

2 (1)

  Unknown

7

1

5

1

2

0

Histologic subtype, n (%)

  ALM

129 (100)

 

82 (100)

 

47 (100)

 

  SMM

 

617 (88)c

 

402 (89)c

 

215 (88)c

  LMM

 

60 (9)

 

43 (9)

 

17 (7)

  NM

 

22 (3)

 

9 (2)

 

13 (5)

Clark level, n (%)

  II

57 (45)

174 (25)b

49 (60)

154 (34)b

8 (17)

20 (8)c

  III

37 (29)

369 (53)

24 (29)

233 (52)

13 (28)

136 (56)

  IV

34 (27)

153 (22)

9 (11)

65 (14)

25 (54)

88 (36)

  V

0

1 (<1)

0

0

0

1 (<1)

  Unknown

1

2

0

2

1

0

Breslow thickness, mm

  Median (range)

0.7 (0.2–1.0)

0.7 (0.1–1.0)

0.5 (0.2–0.8)

0.6 (0.1–0.8)

0.9 (0.5–1.0)

0.9 (0.3–1.0)

Mitosis, n (%)

  <1/mm2

69 (68)

414 (63)

50 (82)

309 (7)

19 (48)

105 (45)

  ≥1/mm2

32 (32)

246 (37)

11 (18)

118 (28)

21 (53)

128 (55)

  Unknown

28

39

21

27

7

12

  Median (range)

0 (0–9)

0 (0–20)

0 (0–4)

0 (0–5)

1.0 (0–9.0)

1.0 (0–20.0)

Ulceration, n (%)

  Absent

121 (95)

677 (97)

82 (100)

454 (100)

40 (85)

224 (91)

  Present

7 (5)

21 (3)

0

0

7 (15)

21 (9)

 Breslow thickness <0.8 mm, n (%)

    

3 (6)

10 (4)

 Breslow thickness ≥0.8 mm, n (%)

    

4 (9)

11 (5)

  Unknown

1

1

0

0

0

0

Lymphovascular invasion, n (%)

  Absent

127 (98)

670 (99)

82 (100)

437 (99)

45 (96)

233 (99)

  Present

2 (2)

5 (1)

0

3 (1)

2 (4)

2 (1)

  Unknown

0

24

0

14

0

10

Perineural invasion, n (%)

  Absent

127 (98)

675 (100)

82 (100)

440 (100)

45 (96)

235 (100)c

  Present

2 (2)

0

0)

0

2 (4)

0

  Unknown

0

24

0

14

0

10

Regression, n (%)

  Absent

101 (80)

463 (70)c

65 (79)c

288 (66)c

36 (80)

175 (77)c

  Present

26 (20)

200 (30)

17 (2)

148 (34)

9 (20)

52 (23)

  Unknown

2

36

1

18

2

18

Tumor-infiltrating lymphocytes, n (%)

 Non-brisk/minimal

119 (98)

566 (86)b

79 (98)

374 (87)c

40 (100)

192 (85)c

 Brisk

2 (2)

89 (14)

2 (2)

55 (13)

0

34 (15)

 Unknown

8

44

1

25

7

19

Vertical growth phase, n (%)

  Absent

60 (50)

116 (18)b

53 (66)

104 (24)b

7 (17)

12 (5)c

  Present

61 (50)

538 (82)

27 (34)

321 (76)

34 (83)

217 (95)

  Unknown

8

45

2

29

6

16

Microsatellitosis, n (%)

  Absent

129 (100)

672 (99)

82 (100)

438 (100)

47 (100)

234 (99)

  Present

0

4 (1)

0

2 (<1)

0

2 (1)

  Unknown

0

23

0

14

0

9

Predominant cytology, n (%)

 Epithelioid

88 (70)

392 (93)b

63 (77)

274 (94)b

25 (58)

118 (91)b

  Spindle

9 (7)

18 (4)

3 (4)

11 (4)

6 (14)

7 (5)

  Nevoid

28 (22)

10 (2)

16 (20)

5 (2)

12 (28)

5 (4)

  Unknown

4

279

0

164

4

115

Sentinel lymph nodes, n (%)

  Negative

64 (83)

670 (96)b

36 (88)

444 (98)c

28 (78)

226 (92)c

  Positive

13 (17)

29 (4)

5 (12)

10 (2)

8 (22)

19 (8)

  Unknown

52

0

48

0

11

0

Number of positive SLNs

 N

13

29

5

10

8

19

 Median (range)

1 (1–4)

1 (1–2)

1.0 (1.0–1.0)

1.0 (1.0–2.0)

1.0 (1.0–4.0)

1.0 (1.0–2.0)

Non-sentinel lymph nodes, n (%)

  Negative

12 (60)

127 (99)b

5 (50)

85 (100)b

7 (70)

42 (98)c

  Positive

8 (40)

1 (1)

5 (50)

0

3 (30)

1 (2)

  Unknown

109

571

72

369

37

202

Number of positive non-SLNs

 n

8

1

5

0

3

1

 Median (range)

3 (1–10)

4 (4–4)

3.0 (1.0–4.0)

7.0 (1.0–10.0)

4.0 (4.0–4.0)

Local recurrence, n (%)

  No

105 (94)

697 (100)b

67 (96)

452 (100)c

38 (90)

245 (100)b

  Yes

7 (6)

2 (<1)

3 (4)

2 (<1)

4 (10)

0

  Unknown

17

0

12

0

5

0

Distant metastases, n (%)

  No

117 (91)

687 (98)b

77 (94)

449 (99)c

40 (85)

238 (97)c

  Yes

12 (9)

12 (2)

5 (6)

5 (1)

7 (15)

7 (3)

Systemic therapy, n (%)

  No

119 (92)

688 (98)

77 (94)

451 (99)

42 (89)

237 (97)

  Yes

10 (8)

11 (2)

5 (6)

3 (1)

5 (11)

8 (3)

  1. ALM acral lentiginous melanoma, SLNs sentinel lymph nodes.
  2. aIncludes superficial spreading, lentigo maligna, and nodular melanoma.
  3. bp < 0.001.
  4. cp < 0.05.